JPH06294941A - Sunshine guiding device - Google Patents

Abstract

PURPOSE:To provide a sunshine guiding device which can obtain a large quantity of collected light although it is a fixed type. CONSTITUTION:This device has plural linear Fresnel plates 1, a Fresnel lens 2 arranged on the transmission side of the linear Fresnel plates 1, and a photodetecting element 3 which is arranged nearby the focus of the Fresnel lens 2; and the linear Fresnel plates 1 are arranged slantingly to the Fresnel lens 2 so as to vary variation in the angle of sunshine incidence in a time zone or season zone of photodetection with the time or seasons to a smaller variation angle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for collecting sunlight and guiding it with an optical fiber to utilize it for indoor lighting, etc. The present invention relates to a solar light guiding device that collectively guides light to a light receiving unit.

[0002]

2. Description of the Related Art Conventionally, a solar light guide device for collecting sunlight using a Fresnel lens or a reflecting mirror and guiding the collected light indoors using an optical fiber or an optical duct is used as illumination. Devices having various mechanisms have already been proposed and put into practical use. What collects light with the above Fresnel lens and guides this with an optical fiber is an optical fiber bundle with a diameter of about 1 cm including a protective tube, and it can be placed anywhere in the existing room several tens of meters away from the daylighting place.
Light can be guided with only a small amount of attenuation, but in order to introduce direct sunlight that changes the incident direction depending on the season and time into the optical fiber bundle with such a small cross-sectional area, it is necessary to use optical sensors, servomotors and optical sensors. A complicated and expensive tracking device that combines a microcomputer etc. that controls the servomotor based on the output signal is attached to the light receiving part, so that the entire light receiving part including the Fresnel lens and the end of the optical fiber is tracked to the sun. A moving device was needed.

[0003]

On the other hand, when sunlight is guided by a fixed Fresnel lens, the incident angle of the sunlight on the Fresnel lens changes with time, and the sunlight is condensed by the Fresnel lens accordingly. Since the point also moves on the line parallel to the Fresnel lens, passing through the focal point of the Fresnel lens, in the case where the position of the light receiving element with a limited size with respect to the Fresnel lens is fixed, the sunlight collected by the Fresnel lens is Even if light can be received by the light receiving element surface at a certain time, the light collecting position will deviate from the light receiving element surface over time, and there will be a problem that the light cannot be guided to the optical fiber.

For example, when a Fresnel lens having a focal length of 318 mm and a light receiving element having a diameter of 25 mm are combined and the center of the light receiving surface of the light receiving element is installed at the focal position of the Fresnel lens, the light receiving element viewed from the center of the Fresnel lens The visual diameter angle of is 4.5 °, and when the Fresnel lens and the light receiving element are fixed in this way, sunlight can receive light for only 18 minutes.

To solve this problem, if a wide light receiving element is used, the light receiving time in the fixed system can be extended to about 1 hour, but the size of the light receiving element can be economically manufactured. Since there is a limit, in order to extend the receivable time beyond that, it is necessary to use a Fresnel lens with a shorter focal length. Becomes smaller, resulting in a problem that the amount of light collected becomes smaller.

In view of the above problems of the conventional solar light guide device, it is an object of the present invention to provide a fixed-type solar light guide device which can obtain a large amount of light.

[0007]

According to the present invention, a plurality of linear Fresnel plates, a Fresnel lens arranged on the transmission side of the linear Fresnel plate, and a light receiving element arranged near the focal point of the Fresnel lens are provided. The linear light Fresnel plate is arranged so as to be inclined with respect to the Fresnel lens so that the linear Fresnel plate changes the incident angle of the sunlight in the time zone or the seasonal zone of receiving light to a smaller variation angle. It is an optical device.

[0008]

According to the present invention, each time the sunlight passes through the plurality of linear Fresnel plates, the transmission angle corresponding to the incident angle is focused, and the sunlight is received by the light receiving element via the Fresnel lens.
As a result, by selecting the Fresnel angle of the linear Fresnel plate installed on the incident side of the Fresnel lens, the installation angle for the Fresnel lens, and the number of installations, sunlight that moves at an incident angle of 15 ° per hour can be converted into a linear combination of these. After passing through the Fresnel plate, it can be limited to a smaller moving angle, and light can be guided for several hours onto the surface of the light receiving element whose size is limited and the installation position is fixed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings with reference to the drawings. In FIG. 1, the linear Fresnel plate 1 used in this example was an acrylic single-sided Fresnel plate having a plate thickness of 2 mm, a groove width of 1 mm, and a Fresnel angle of 28.8 °. However, the configuration of the linear Fresnel plate that can be used in the present invention is not limited to that shown in FIG. 1. For example, when linear Fresnel plates having different Fresnel angles are used, the same purpose can be satisfied by selecting an installation angle suitable for the linear Fresnel plates. .

The relationship between the incident angle and the transmission angle of the linear Fresnel plate 1 is shown in FIG. 2, and Table 1 shows the refraction characteristics of the linear Fresnel plate 1. From Table 1, for example, smooth surface P
(See Fig. 2) The ray incident on the incident angle θ ₁ = 60 ° is
It can be seen that the light exits from the Fresnel surface F at a transmission angle θ ₂ = 75 °. Also, due to the physical properties of light rays, contrary to the above,
A ray incident on the Fresnel surface F at an incident angle θ ₂ = 75 ° is
It is also possible to go out from the smooth surface P at a transmission angle θ ₁ = 60 °.

[0011]

[Table 1]

When the refraction characteristics shown in Table 1 are examined, the smooth surface P
Even if the incident angle θ ₁ changes in the range of 0 ° to 30 °, the transmission angle θ ₂ from the Fresnel surface F is 41.1 ° to 5 °.
It can be seen that the change is only 1.1 °, that is, 10 °. If this relationship is utilized, the change of the incident angle of sunlight in the range of 9 ° to 30 ° with respect to the smooth surface P, that is, the range of 2 hours is 10
It seems that it can be accommodated within (°) (focusing), but in reality, the incident angle θ ₁ to the linear Fresnel plate 1 becomes too small and the loss due to reflection on the surface of the linear Fresnel plate 1 is large, and the linear Fresnel plate 1 Since only the light of sin θ (direction perpendicular to the smooth surface P) is incident on the area of, it is difficult to put to practical use.

Next, in Table 1, the incident angle θ from 30 °
_If a large range of ₁ , for example, an incident angle θ ₁ = 30 ° to 45 ° is aimed at, a variation range of the incident angle θ ₁ is 15 °.
The width of the transmission angle θ ₂ is 51.1 ° to 61.9 °, which is 1
The focusing effect is small because it changes in the range of 0.9 degree.

On the other hand, the Fresnel surface F side is used as the incident surface, and for example, an incident angle θ _{2 in the} range of 18.5 ° from 113.5 ° (time t ₁ ) to 132.0 ° (time t ₂ ) is used. Then, the range of the transmission angle θ ₁ can be set within a range of 10 ° from 95 ° to 105 °. Moreover, the incident angle θ ₂ is 13
The incident angle θ _{2 with} respect to the Fresnel inclined surface at 2.0 ° is
As shown in FIG. 3, since it can be set at 19.2 °, the surface reflection loss is considerably small. Also, sin θ ₂ = 0.74
Since it is 3, the incident light amount with respect to the linear Fresnel area is considerably large, which is an angle suitable for practical use.

Utilizing the relationship between the incident angle and the transmission angle described above,
When two linear Fresnel plates 1 shown in FIG. 1 are prepared and combined in the arrangement shown in FIG. 4, the relationship between the incident angle θ i and the transmission angle θ ₀ is as shown in Table 2, which is ± 10 with respect to vertical light.゜, that is, 2
The deflection width of the transmission angle θ ₀ of the light beam with the 0 ° deflection width is 6.7 °, and the deflection width of the transmission angle θ ₀ of the light beam with the 20 ° deflection width of 40 ° is 12.3 °. It can fit within the range. In the figure, each linear Fresnel plate 1a,
1b are arranged at an acute angle with their one ends abutting, and the upper linear Fresnel plate 1a is arranged at an angle of 30 ° from the horizontal line with the Fresnel surface F as the incident side, and the lower linear Fresnel plate 1a is arranged. The plate 1b has its Fresnel angle tilted in the opposite direction to the upper linear Fresnel plate 1a,
It is placed at an angle of 10 ° from the horizon.

[0016]

[Table 2]

Here, at the front surface (sunlight incident side) of the apparatus in which a Fresnel lens having a focal length of 318 mm and a light receiving element having a diameter of 25 mm are combined at the focal position thereof, as shown in FIG.
By disposing the multi-layer linear Fresnel plate composed of the linear Fresnel plates 1a and 1b, a range of 84.7 ° to 96.5 ° with respect to the Fresnel lens plane, that is, 1
It is now possible to focus a light beam with a swing width of 1.8 ° on the light-receiving element surface, extending the sunlight-receivable time by approximately 2.6 times as compared with the case where no linear Fresnel plate is used. It becomes possible.

If the number of linear Fresnel plates 1 used is increased by using the configuration described above, it becomes possible to set a ray having a very large deflection angle within a small deflection angle, and theoretically 180 ° from morning to evening. It is possible to introduce sunlight moving in the sky into a light receiving element having a limited diameter.
However, when the number of combinations of the linear Fresnel plate 1 is increased, the light loss due to absorption and reflection on the linear Fresnel plate 1 is increased, and the focal diameter of the Fresnel lens is enlarged (blurred) due to the manufacturing accuracy of the linear Fresnel plate 1. ) Will also increase. For this reason, the combined number of the linear Fresnel plates 1 configured in multiple layers as the solar light guide device is optimally two in practice.

[Embodiment 1] FIG.
As shown in FIG. 2, two acrylic linear Fresnel plates 1a and 1b each having a length of 420 × width of 420 × thickness of 2 mm, and an acrylic Fresnel convex lens having a diameter of 381 mm, a thickness of 4 mm, and a focal length of 318 mm (hereinafter referred to as Fresnel lens). ) 2 and the light receiving element 3 having a light receiving surface diameter of 25 mm, the light receiving device A was manufactured. If this light receiving device A is fixed in the incident direction of sunlight, the light receiving time is 66
Minutes, 17 days a year. Therefore, as shown in FIG. 6, the light receiving device A is housed in a box body 5 having an open upper portion, and the box body 5 is rotated in the X direction (east-west direction) and / or the Y direction (south-north direction). The adjustment mechanism B is provided so that it can be performed.

That is, the adjusting mechanism B includes two rotary shafts 5a (only the front side is shown) protruding from the side wall of the box body 5 in the X direction, and a frame 6 rotatably supporting the rotary shafts 5a. And the rotary shaft 5a attached to the frame 6
A first drive device 7 having a built-in pulley (not shown) for rotating the same, and a cable 8 containing an endless wire (not shown) for rotating the pulley in the first drive device 7, A pedestal 8 that rotatably supports the box body 5 and the frame 6, and a second drive device 9 that is attached to the pedestal 8 and that has a built-in pulley (not shown) for rotating the frame 6 in the X direction. It mainly comprises a cable 10 accommodating an endless wire (not shown) for rotating a pulley in the second drive device 9.

The other end of the wire is extended to the interior of the building and connected to a handle (not shown) so that the angle can be adjusted from the room every hour in the east-west direction and twice a month in the north-south direction. I am trying. In addition, the handle inside the room to which the wire is connected has a scale for confirming the operation amount, but in fine weather the optimal adjustment point can also be confirmed by shining a light emitter (described later) installed on the indoor ceiling. it can.

Further, since the exit end of the light receiving device A in the box 5 has a diameter of 5 mm, the exit end is 50 μm in diameter.
Connected to one end of a 10 m long light guide 4 (outer diameter 9 mm made of soft PVC), which is a bundle of multi-component glass optical fibers of 5 mm in diameter, and the other end of the light guide 4 to the indoor ceiling of the building. It was connected to the attached light emitter.

FIG. 7 shows the structure of the light emitter. In the figure, the light emitter 13 is housed in the case 14, and the light emitting film 16 (SOLF manufactured by Sumitomo 3M Limited) is attached to the inner surface of the acrylic tube 15 having an outer diameter of 100 mm and a length of 900 mm. , A light emitting portion in which an aluminum white plate 17 is obliquely inserted in the axial direction of the acrylic tube 15, and a reflecting mirror 18 provided on the back side of the acrylic tube 15 and having a parabolic cross section with aluminum vapor-deposited on the back surface of the acrylic plate.
And 900 mm × 320 mm × 2 that covers the surface of the light emitting unit 14.
mm of transparent polycarbonate plate 19. When these devices are used and the Fresnel lens 2 surface of the solar light guide device is installed almost vertically to the sunlight during fine weather in winter, all parts of the outer surface of the polycarbonate plate 19 of the light emitter 13 installed in an indoor dark place. And an illuminance of 360 to 420 lux was obtained.

[Embodiment 2] Referring to FIG. 8, four acrylic linear Fresnel plates 1a of 300 × 240 × 2 mm and four acrylic linear Fresnel plates of 300 × 220 × 2 mm having the structure shown in FIG. 1b and external dimensions 2
Four Fresnel lenses consisting of 79 x 279 x 2.4 mm (effective size 266 x 266 mm, focal length 178 m
m) 2 and two light receiving elements 3 each having a light receiving surface size of 60 × 15 mm are prepared. First, the linear Fresnel plate 1
The Fresnel surfaces of a and 1b are made incident sides, and the Fresnel angles of the linear Fresnel plates 1a and 1b are made opposite to each other, and one end of the linear Fresnel plates 1a and 1b is brought into contact with each other to form an acute angle. The Fresnel lens 2 is arranged at an acute angle with respect to the lower linear Fresnel plate 1b with its free end as a tip to form a light guide portion, and then the focus of the Fresnel lens 2 is concentrated within a predetermined range. The light guides are arranged symmetrically, and one light receiving element 3 is arranged within the predetermined range to form a light receiving device. Further, the light receiving device thus configured is vertically changed from 0 ° to 90 °. By arranging another set symmetrically with respect to the line, a solar light guide device in which the Fresnel lens 2 is continuous in a substantially arc shape was manufactured.

Reference numeral 20 denotes a housing member for housing the above solar light guiding device, which has a length of 828 x a height of 440 x a width of 314 mm, a front surface of which is made of a substantially semicircular hard vinyl chloride resin plate, and a bottom surface 21. Is made of a plate-shaped hard vinyl chloride resin plate, and a reinforcing member 22 having a thickness of 10 mm is attached to both sides of the bottom surface 21.
The rotary shaft 23 is provided in the horizontal direction. Also,
A portion connecting the upper surface and the side surface of the storage member in a strip shape is covered with a transparent acrylic plate 24 having a thickness of 2 mm. By installing the rotary shafts 23, 23 of the solar light guide device having such a configuration in the east and the west and inclining the top toward the south-south central altitude of the day, as shown in the solar light collecting path in FIG. The device remains fixed at 3.3 ° (06:13) to 176.
It is possible to collect almost all day sunlight up to 7 ° (17:47) on the surface of the light receiving element 3 and guide it through the optical fiber light guide 4 to the light emitter provided in the building. The structure of the light emitter is 50 mm in diameter and 500 m in length.
500mm x 160mm surface using m acrylic tube
In the case of using the light emitting device of No. 3, it was possible to obtain an illuminance of 680 to 1050 lux on the surface plate on a sunny day in early March.

The linear Fresnel plate 1 shown in FIG.
At the installation angles of a, 1b and Fresnel lens 2, the incident light around 9 o'clock and around 15 o'clock is slightly less than at other times, but if the installation angle is changed and the morning and evening incident time is reduced, the incident light during the daytime will be reduced. Can be more uniform. Further, since the solar light guide device shown in FIG. 8 uses the light receiving element 3 having a width of 15 mm, the maximum number of days that light can be incident is 1 without changing the tilt angle.
It is 8.7 days. Therefore, as in the case of the first embodiment, if a wire for rotating it is attached to the rotary shaft 23 and the tilt angle is adjusted by the wire about every two weeks indoors, the annual sun It becomes possible to guide light.

The number of adjustments can be reduced by expanding the width of the light receiving element 3. In extreme cases, Figure 8
When the width of the light receiving element is expanded to 155 mm in the device shown in (1), it is possible to guide the annual sunlight while the solar light guide device is fixedly installed according to the inclination of the installation place. However, increasing the width of the light receiving element 3 leads to an increase in the cost of the light receiving element, and further, it is necessary to increase the diameter of the optical fiber, which is not preferable in consideration of cost.

Further, in the above embodiment, the adjusting mechanism is composed of the pulley and the wire guided to the room, but the present invention is not limited to this.
Any device can be used as long as it can change the inclination angle of the box body. Further, although the solar light guide device of the present invention is configured by the two linear Fresnel plates in the above-described first embodiment, the present invention is not limited to this and may be a multilayer having more layers.

Further, although the solar light guiding device of the present invention is composed of four sets of linear Fresnel plates in the second embodiment, it is not limited to this and may be more or less. Further, although the Fresnel lens is configured to have a continuous circular arc in the second embodiment, the present invention is not limited to this, and may have a discontinuous circular arc.

[0030]

As is apparent from the above description, according to the present invention, the transmission angle corresponding to the incident angle is converged every time the sunlight passes through the plurality of linear Fresnel plates.
Since light is received by the light receiving element via the Fresnel lens, efficient light collection can be performed with a small number of light receiving elements. Therefore, by using these combined linear Fresnel plates, it is possible to limit incident light to a smaller movement angle after passing through it, and to guide light even to the light receiving element surface where the size is limited and the installation position is fixed. It is possible to extend the time.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a linear Fresnel plate according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a relationship between an incident angle and a transmission angle in the linear Fresnel plate shown in FIG.

FIG. 3 is an explanatory diagram showing a relationship between a Fresnel inclination angle and an incident angle in an example.

FIG. 4 is an explanatory diagram showing a combined arrangement of linear Fresnel plates according to the embodiment.

FIG. 5 is a configuration diagram of the solar light guiding device of the first embodiment.

FIG. 6 is a configuration diagram of a sunlight guiding device with an adjusting mechanism according to the embodiment.

FIG. 7 is a perspective view showing a configuration of a light emitting device according to the embodiment.

FIG. 8 is a cross-sectional view showing the configuration of the solar light guiding device of the second embodiment.

[Explanation of symbols]

 1 linear Fresnel plate 2 Fresnel lens 3 light receiving element 4 light guide 5 box 6 frame 7 first drive device 8 cable 9 second drive device 10 cable 13 light emitter

Claims (1)

[Claims] 1. A plurality of linear Fresnel plates and a Fresnel lens arranged on the transmission side of the linear Fresnel plates,
A linear light Fresnel plate having a light-receiving element arranged near the focal point of the Fresnel lens, so that the linear Fresnel plate changes a change in the incident angle of sunlight in a time zone or a seasonal zone in which light is received to a smaller change angle. The solar light guide device is arranged so as to be inclined with respect to the Fresnel lens.